This invention relates most closely to removeable collar assemblies for connecting battery terminals to cables or wires, for example, in automobiles.
Several types of conductive collars are well known and used for securing electrical cables to battery terminal posts. Everyone is familiar with the common auto battery cable neck brace, which is slotted and fits over and around the terminal. It is secured and removed by tightening or loosening a screw fitted through two opposed openings in the slot area of the brace. Generally, either a wrench or screwdriver is required for installation and removal.
Another somewhat less familiar type of connector uses an insulating collar having a spring-loaded conductive probe or rod therethrough which forcibly contacts the battery post, or in some cases, is forced into an opening in the post and is held there by the spring compression tension. Here also a wrench is needed to install or remove the connector.
The problems and disadvantages of existing battery cable connectors are well-appreciated and include, in addition to the just-noted necessity of a tool or tools for installation or removal, corrosion and corrosion by-products used by less than air-tight contact between the connector and the battery post. Spark-gaps will, of course, contribute to corrosion and result in deterioration of both the electrical contact and the terminals and connector materials themselves. Gaps tend to increase as a result of heating, which causes expansion and contraction in the connection area during power transfers to and from the battery.
The corrosion problem emphasizes the need for as secure a contact as possible between a cable connector and battery terminal post. This has up to now mandated the use of tool strength in the installation of the connection. The obvious drawback is the requirement of a tool and the time spent in removing the connector.
While this drawback may not be particularly serious in the case of, for example, a single car battery, it becomes much more of a problem in multiple-battery power source situations, such as battery-bank power supplies used idn laboratories or in emergency power back-up systems.
Another growing multiple-battery application is found in the all-electric automobile, in which typically banks of ten to twenty batteries or more are used to power the car.
In these latter applications, large and constant power transfers through the conductors produce rapid foul-up of the connections, necessitating frequent cleaning of the battery posts and collars. The downtime from just the removal and re-installation of the connectors is significant in these situations. It would thus be of obvious value to provide an electrical cable connector which could be easily and quickly placed on and removed from a battery terminal, without sacrificing the tightness and security of standard battery or post collar connectors.